


Solar Flare

by ToukoTai



Category: Big Hero 6 (2014)
Genre: Angst, Gen, Happy Ending, fuck I dunno
Language: English
Status: Completed
Published: 2015-04-01
Updated: 2015-04-01
Packaged: 2018-03-20 15:53:01
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,302
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/3656136
Author URL: https://archiveofourown.org/users/ToukoTai/pseuds/ToukoTai
Summary: <blockquote class="userstuff">
              <p>Being twenty one is tough, it's tougher when you've spent the last three years being experimented on. Tougher still when you can't even think straight. Good thing your brother's got your back. Even if you don't want him to.</p>
            </blockquote>





	Solar Flare

**Author's Note:**

> based on [this](http://40.media.tumblr.com/1af610a3ac6ec8c533ed6e6353456b35/tumblr_nkq8wosAW81u4760co1_500.jpg) picture by frick-sticks on tumblr.  
> Thanks for the helping crediting.  
> ha, okay yeah, this wasn't one of the things I had lined up it just sort of happened last night.
> 
> backstory: Tadashi gets found in the wreckage burning, unhurt and unconscious. Experimental chemicals from someone's project interacted with the fire and him in a new fun way. He gets kidnapped and experimented on for the next three years, and he's mentally unstable from the chemicals in the first place. Hiro and friends still think he died in the fire. He escapes and tries to set fire to everything because he's not exactly sane. Big Hero Six manage to subdue him, story picks up from there.

Anger. He’s always angry now. It burns just as bright as the flames, his flames. First it was anger at himself, for doing something so stupid. Then it was anger at what was being done to him and now. Now he’s just plain _angry_.

He’s not stupid, he knows whatever they did to him affected him more than just the flames.

Affected his mind.

There’s a part of him deep in the back, buried under the fire and anger, that’s wailing in terror over what he’s become. He doesn’t care to listen to that part. Anger is so much easier.

Even now.

“Hiro. Let me out, _now_.” Time was that tone would have Hiro scrambling to obey. But now, Hiro stares at him coolly from the other side of the containment unit. Folds his arms in the unimpressed gesture of teenagers everywhere.

“Yeah, I’m gonna say no. Sorry bro, you haven’t convinced me you won’t try to burn the entire city down if I let you out. Ya know, _again_.” Hiro ignores the frustrated growl and hand slam that gets him. He steps closer to the tank instead of away. “I’m going to.” He tells the angry, fire wraith of his brother. “I am going to let you out of there. I promise. Cross my heart, pinkie swear and hope to die.” His raises his hand and traces an X lightly over his heart.  “As soon as we figure out how to reverse this.” Hiro waves a hand encompassing all of the fire and molten skin and glowing, pupiless, eyes.

“You’ve been _trying_ for weeks. _Let me out_.” His fists slam heavily against the containment glass; his flames grow huge, flaring out with his wrath. The glass doesn’t shake, it doesn’t melt. It stays as it is. And so does Hiro.

He’s standing in the same place, in the same way, watching him with calm brown eyes. He’s not the same Hiro Tadashi left behind, that much is certain. He’s older and stronger and didn’t even twitch. He doesn’t scare easily, this seventeen year old brother.  Hiro takes another step toward him, and leans his forehead against the glass, eyes closed. (He’s tall enough now to be at eye level.)

“I know. I’m sorry. I can’t. But!” He whirls away suddenly all energy and sunshine, throws a grin at him as he starts walking backward to the door. “I’m there! That’s why I came so early today. I figured it out; I figured it all out! I just have to finish a few calculations. And do some test runs. But I’m _there_.” He stared in open mouthed wonder as Hiro vanished behind the door. Belatedly the anger came roaring back, he banged his fists against the glass.

“Hiro! Get back here! Don’t you dare change me again! _Hiro!_ ”

 

_“He’s really not on board with this whole thing is he?”_

_“Not in the least.” Hiro said, watching the diagnostics and status screens in front of him. “I tried explaining exactly what I was going to do, but he wasn’t having any of it.” He tapped at a screen and then scribbled some notes on the clipboard in front of him. “This’ll be done in half an hour, then I just have to convince him to cooperate.”_

_“Why? Couldn’t you just knock him out?” Gogo asked, hands on hips._

_“Well, yes. But he’s had this done to him against his will to start with; I’d like it to be his choice.” Hiro looks up at her, his mouth opens and then closes as the alarm goes off. “Guess we’ll have to wait.” Gogo nodded, already heading to the door, fitting her helmet on. Hiro Jogs after her, stripping off his lab coat as he went._

_“Should be ready by the time we get back.”_

 

It’s been a long time since Hiro’s early morning visit. And the part of Tadashi curled deep down inside is starting to worry. The rest of him is furious that Hiro thinks he can change him back. Can toy with him; treat him like another experiment or a bot gone wrong. Tadashi doesn’t want to go back. He’s not a problem to fix. He’s just _fine_ the way he is right now. If only the rest of the world, his brother included could see that. His musing is cut off when the door slides open and Gogo storms into the room.

She doesn’t waste any time, strides right up to his unit and slams her fist against the glass. She looks as furious as he feels and as scared and worried as that distant part of himself is.

“Tell me where they are.” She hisses and he sneers at her. “The ones who did this to you, tell _me. Where. They. Are._ ” And like all the times before he snarls back at her.

“ _No._ ” She snaps at that. Screams, and slams her fist against the tank, slams it again, goes for a third time, but Wasabi grabs her and pulls her back.  It’s not just about him anymore he realizes. A growing pit in the base of his stomach. It’s not just him, because Hiro said it didn’t matter if they found who did this, Hiro would fix it all on his own if he had to. But Gogo is scaredangryterrified, the other’s aren’t much better.

_And Hiro isn’t there._

“They wanted you back Tadashi.” Honey’s voice is meek, her hands wringing around each other. “They wanted you back and they knew Hiro had you.” Tadashi doesn’t want to hear where this is going. Doesn’t want to hear how he was the cause of his brother’s ruin again. “They tricked us.” She says. “They got into Baymax somehow. Tadashi,” He doesn’t want to hear this, he _can’t_ hear this. “They have Hiro.”

It feels like ice water has been dropped down his spine. Numbness spreading to his fingers and toes. He slumps back against the tank, lets the cool, thick glass support his body.

“Will you look at that…” He doesn’t notice that his flames have completely gone out, that his lava red orange skin is now back to normal. Doesn’t notice any of that over the repeated phrase: ‘They have Hiro.’

“That’s why we need to know.” Gogo’s voice is rough, from screaming, from fear. “You need to tell us where they are.” Tadashi looks up from the floor of the unit where his gaze had landed to meet her eyes.

“I come with.” He says with perfect conviction. “If you’re going after Hiro, I come with.” Gogo opens and closes her mouth.

“Fine.” She agrees. Tadashi narrows his eyes, that was too easy.

“On oooooone condition.” Fred interjects; he pulls a hand out from behind his back. When Tadashi sees the syringe, his anger that had been kept down boiled over. A veil of red in front of his vision as the flames roared back into being. Until Gogo slams her fist into the glass again, it makes him pause, makes him remember: They have Hiro.

“Hiro wasn’t going to change you back!” Gogo, frustrated finally spits out. It brings things to a crashing halt for Tadashi. “You _know_ you’re not right, mentally. He wanted to fix that. We promise you, this isn’t going to take away what you are, it’s going to give _you_ back.”

“Fine!” Tadashi hisses. He’s not fine with it, but Hiro’s out there. They have Hiro, Hiro took the fall for him, they could be doing _anything_ to his baby brother. And he needs to get Hiro back, no matter the cost. The procedure is explained to him. He’s going to be put under first, in case of any sudden flare up’s, then injected with Hiro’s serum. Hopefully he’d wake up in full control of himself. Honey and Gogo busy themselves with setting things up as Wasabi gives him the final instructions from the clip board Hiro always carried around with him.

“His notes say…” Wasabi pauses for a second, and squints at the writing on the page in front of him. “The notes say you might want to sit down.” Tadashi slowly lowers himself into a cross-legged seating position on the floor of the unit.

“Why?” He asks, partly from curiosity and partly to distract from the burning anger still under his skin.

“He wrote, ‘cognitive recalibration bonehead, why do you think?’ right under that.” The brief flare of amusement and fondness manages to tamper down the rage. It’s the last thing Tadashi hears for a while, Honey Lemon and Gogo have finished setting things up and Fred salutes him once before hitting the switch. The unit fills with grey gas and Tadashi has to fight to keep his flames down, to breathe in slowly and deeply. To keep his anger and terror down, because Hiro needs him right now. Not tomorrow, not later in the week, but right now.

He left Hiro behind once. By accident, sure. But he still did. He wasn’t there when Hiro needed him and Hiro wasn’t there when _he_ had needed Hiro. But Hiro had been there the past couple weeks, months really. Refused to leave, no matter what Tadashi said or yelled or screamed at him. Worked round the clock, night after night, day after day, until the bags under his eyes made him look like a panda and a few times he hadn’t even been walking in a straight line from fatigue. All to make this. All so Tadashi could be _himself_ again, without taking away from what he is now. The smoke curls around in his head, he doesn’t notice when he blacks out.

 

When he wakes up, it’s only been an hour and he’s flat on his back on a medical table with Honey Lemon shining a pen light in his eye and Fred sticking a bright pink Hello Kitty band aide over the injection site on his neck.

“How do you feel?” Sitting up is hard and his muscles feel sore, but he manages to get his legs over the side and body mostly upright.

“Like I got dragged by the semi that ran me over.” He says honestly, voice rough and hoarse, she giggles at him. “I’m _sorry_.” Now that his head is quiet, that his mind is calm, he can feel rightfully dismayed and embarrassed about himself. Honey Lemon smiles at him, teeth white and straight but something like sadness pulling at the edges.

“Oh, Tadashi. It’s okay.” It’s not really. It’s really not. He can’t believe he tried to burn down the city, he doesn’t even know why he tried to do that. Memories flash through in bits and pieces, a red haze over all of them. With a groan, Tadashi raises a hand to swipe down his face and freezes. Pink skin with palm lines and the fine hairs on the back of his arms greet him, everything perfectly normal. The flash of rage that comes is no where near what it had been previously, but it’s there. And somewhat rational. They _promised_ they wouldn’t turn him back. They _promised_.

It dies as quickly as it comes because his skin turns molten orange yellow and tiny spits of flame dance over his fingers with the flash of rage. A blink and his hand is back to normal. Tadashi concentrates, his hand and arm burst into flame. Dampens back to normal with barely a thought.

“Very good.” Honey Lemon claps her hands. “Near perfect control!”

“No raging inferno feelings?” Wasabi prods carefully.

“No darkside urges?” Fred juts in, not nearly as carefully. Tadashi shakes his head. No, no he doesn’t have any. It’s just a calm empty well where the anger used to coil. He forgot how good it felt not to be so angry all the time. His feet kick in the air a little, heels tapping against the metal framework. It’s quiet for a few minutes as Tadashi marvels in the ability to just _feel_ again. To be able to follow one thought to the end without the burning red of anger coming up to disrupt it. There’s only one place his thoughts run to.

The serum was made specifically for him. Created in a way where it would probably have been easier to just reverse whatever had been done to him. But special care had been taken to make sure that he remained essentially the same, that the way back to his right mind was as simple and painless as possible. Someone had spent a lot of time and care on the serum. On him. Someone had cared a whole awful lot about his peace of mind.

“Hiro!” Standing up is almost a disaster, if Fred hadn’t been there to catch him when his legs buckle under him.

“Easy dude. Can’t rescue the little guy if you can’t walk right?” Fred’s hands under his arms brings Tadashi’s attention back to the experimental suit like armor over his body. He feels sick, the slick sticky feeling of the material clinging to his skin but still exposing almost everything. His nails scrabble over the catches, breathing kicking into overdrive.

“Get it off, get it off, get it off.” He chants.

“Whoa whoa whoa.” Wasabi and Fred manage to get him seated back on the table, hands pressed palm down on the surface, breathing heavily through his nose. Fighting off a panic attack and trying to keep his skin from turning into magma.

“You good?” Gogo asks. Tadashi takes a few more deep breaths, his skin crawls against the suit. Wasabi raises an eyebrow when Tadashi shakes his head.

“I can’t.” He says, stumbling over the words. “I need out. Can’t, can’t stay in this.”

“Don’t worry my man.” Fred draws his attention to a section of the wall. Pieces of armor, orange and black, a long dark coat, a visor, heavy gloves, boots, pants, hang on the wall. Every bit of it as different from what he was currently wearing as possible but still _made_ for him. Made to do _more_ then just survive being worn by him. Tadashi’s eyes widen as the implications set in. Fred grins at his surprised look. “Grasshopper’s ten steps ahead, like usual. Little dude never does anything by halves.”

 

Hiro’s not the only one, it seems his brother’s flare for over doing things has spread to the other’s. Or the rest of the team is as worried about Hiro as he is. They don’t leave much intact when they storm the hidden base. They pretty much rip it apart in their wake. No one is ready for them. And well, going back to the place that kept him prisoner, kept him an _experiment_ for the last three years is more then enough for Tadashi to go a tiny little bit overboard when breaking back in to get to Hiro.

(He’s also _terrified_ of what they might be doing to Hiro. What they might be turning him into.)

Tadashi’s rather surprised by how well his friends work together, how well their different fighting styles and tools blend together. How Gogo uses the chaos Honey creates to slip around their foes, how Wasabi follows in Fred’s wake. He hangs back, getting the feel of the way the team works. It’s almost flawless, they’ve obviously had quite a lot of practice in doing this. He  does see a giant gap, in their movements and formations, a gap where Hiro and Baymax would fit.

Speaking of Baymax, Tadashi is not looking forward to tangling with his hacked nursebot. Not after remembering what it was like the last and first time he had. When the team had brought him in. Baymax hits like a truck, is a lot faster then his size and armor would make you think and knows karate with the kind of focus and precision a well trained fighter would.

“We took him once.” Gogo says grimly. “We can do it again.” Honey nods. There’s a whole story here that Tadashi doesn’t know and has no time to ask. There’ll be time once Hiro is back and other things are set straight. Like this whole superhero business in the first place.

As it happens, Baymax turns out to be a non-issue. The robot is slumped over, battery drained outside of the cell Hiro’s in. Hiro himself is curled in the corner of the cell, bloody, bruised and fast asleep. But otherwise untouched. Tadashi can’t help the sigh the relief.

“Oh hey guys.” Hiro says, voice slightly tense but mostly happy when Tadashi wakes him by trying to pick him up. Despite growing in the three years since, Hiro is still on the short side, still easy to wrap his arms around and he’s ten times too light for Tadashi’s taste. “Perfect timing, I was getting a little bored.” His armor’s cracked in places, missing in others. He hisses when Tadashi squeezes him a little too tightly. “Ribs cracked.” Hiro says under his breath, he grins up at Tadashi’s tinted visor. “Sorry I didn’t keep my promise.” He’s talking about being the one to let him out, Tadashi realizes. It hardly matters though, Hiro kept the one that mattered. “Man, it’s good to see you again.”

Tadashi has a hundred and one things to say to him. But he winds up not being able to say any of them at all. Sitting next to his brother’s bedside at the hospital, their friends giving them space under the guise of taking care of Baymax, he’s found that he lost his voice.

“So?” Hiro prompts. “I’m assuming it worked, ‘cause you don’t look like you’re going to punch me or set the building on fire.” In answer Tadashi raised his hand, concentrated and set it alight. Meeting Hiro’s eyes steadily the entire time. Except Hiro’s not looking at him, he’s watching Tadashi’s new trick with delight and a self satisfied smile. “ _Awesome_.” Hiro breathes. He catches Tadashi’s incredulous look. “What? What did you think I was going to do?” Hiro raises an eyebrow in at him.

“I-I thought…I didn’t want to change back.” He finally says and Hiro snickers at him, followed by a wince from the still cracked, healing ribs.

“I know. You screamed it at me enough times.”  Tadashi opens his mouth; he did scream that at Hiro, more than once. And other things too, things he didn’t mean, things he knew would hurt the most. None of what he had voiced seemed to have affected Hiro at the time. At least Hiro hadn’t shown any cracks in front of Tadashi. Which was for the best, at the time Tadashi would have dug in harder if Hiro had shown any weakness.

“Don’t worry about it.” Hiro smirks at him, patting at Tadashi’s knee. Somehow knowing exactly what was going through Tadashi’s mind. “Chemical imbalance in the brain. S’what made you so unstable, more than normal anyway.” Tadashi smiles a little at the dig. Hiro sinks deeper against the pillows, considering everything he’s been doing and the events of the last twenty four hours, he must be tired. Tadashi’s hands die down to normal skin and he absently hitched the blanket up around Hiro’s chest. “If you wanted to,” Hiro starts, voice going quiet as he falls asleep, his eyes had already slipped shut. “Could change you all the way back.”

“I’ll think about it.” Tadashi says, sitting back in the visitor chair, watching Hiro breathe. “Kinda like the name Sunfire. Got a ring to it.”

“Mhmm.” Hiro hums, either missing or not caring about the implications. “Missed you.” He mumbled, last rays of light turning the room soft colors of orange and yellow around them. Tadashi listens to Hiro’s breathing deepen and even out. His hair is coarse and tangled under Tadashi’s fingers as he runs his hand through it.

“Missed you too.”

 

**Author's Note:**

> I imagine after three years of superhero-ing around San Fransokyo, there's very little that throws Hiro off his game any more. Dead brother comes back as the evil wrath filled human torch twin? Normal Tuesday.  
> Not so dead brother taunts you from containment unit? Keep it together until you are FAR from where he can hear or see you, then viciously kick the shit out of a wall. BE THE BIGGER MAN.  
> Shadowy organization that experimented on said not dead brother has kidnapped you? catch some Z's in the cell while you wait for your team to come get you.


End file.
